Solid catalyst for dehydration of mannitol, and method for producing 2, 5-sorbitan and/or isomannide using this catalyst

Abstract

Provided is a solid acid catalyst which enables the production of isomannide and/or 2,5-sorbitan from mannitol with high yield and high safety at low cost. The mannitol may be derived from a cellulose and/or a hemicellulose. The solid acid catalyst for dehydration contains an acid type β-zeolite and/or a Y type zeolite.

The invention claimed is: 
     
       1. A solid, dehydration catalyst for producing 2,5-sorbitan and/or isomannide from mannitol comprising an H-type β zeolite and/or a Y-type zeolite. 
     
     
       2. The solid, dehydration catalyst according to  claim 1  consisting essentially of the H-type β-zeolite. 
     
     
       3. The solid, dehydration catalyst according to  claim 1  consisting essentially of the Y-type zeolite. 
     
     
       4. The solid, dehydration catalyst according to  claim 1 , wherein the H-type β-zeolite and/or Y-type zeolite has a Si/Al atomic composition ratio of 10 to 300. 
     
     
       5. The solid, dehydration catalyst according to  claim 4 , wherein the Si/Al atomic composition ratio of the H-type β-zeolite and/or Y-type zeolite is 25 to 150. 
     
     
       6. The solid, dehydration catalyst according to  claim 5 , wherein the Si/Al atomic composition ratio of the H-type β-zeolite and/or Y-type zeolite is 40 to 100. 
     
     
       7. A process for producing 2,5-sorbitan and/or isomannide from mannitol, comprising the steps of:
 (a) adding the solid, dehydration catalyst according to  claim 1  to mannitol to obtain a reaction mixture, and 
 (b) heating the reaction mixture obtained in step (a) to a temperature of 110° C. to 170° C. at ambient pressure or under reduced pressure. 
 
     
     
       8. The process according to  claim 7 , wherein the amount of the solid, dehydration catalyst is 5 to 50% by weight, based on 100% by weight of the mannitol. 
     
     
       9. The process according to  claim 7 , wherein the solid, dehydration catalyst consists essentially of the H-type β zeolite, and wherein the process further comprises producing isomannide. 
     
     
       10. The process according to  claim 7 , wherein the process further comprises producing isomannide by 1,4-mannitan. 
     
     
       11. The process according to  claim 7 , wherein the solid, dehydration catalyst consists essentially of the Y-type zeolite, and wherein the process further comprises producing 2,5-sorbitan. 
     
     
       12. A process for selectively producing isomannide from mannitol or 2,5-sorbitan from mannitol comprising catalytically dehydrating mannitol by use of any of the compositions selected from the group consisting of an H-type β zeolite, a Y-type zeolite or a mixture thereof.